Leading-in conductor.



W. L. VAN KEUREN.

LEADING-IN CONDUCTOR.

APPLICATION FILED DEC.29.1913. RENEWED FEB. 7. 1918.

1,268,647 Patented June 4,1918.

Witnesses: I Inventor WJJwd VanKeuren,

His Attorney smarts rarnnr enrich.

LLOYD VAN KEUBEN, OF NORTH BERGEN, NEW JERSEY, ASSIGNOE T0 am; 1 ELBOW comm. A CORPORATION OF NEW YORK.

EWING-IN COED'UGME.

'meaeaa s mm r w Patented June a, rare.

Applleaflon filed December as, 1M8, serial Ho. 809,908. Eenewed February 7, 1918. serial Ho. 315,928.

To all whom it may concern:

Be it known that I, Wrnmnm Lnorn VAN Keenan, a citizen of the Umted'States, residing at North Bergen, county of Hudson, State of New Jersey, have invented certam new and useful Improvements in Lead ng- In Conductors, of which the followmg 1s a specification.

My present invent1on relates to improvements in leading-in conductors for meandescent lam s, gas electric lamps, mercury rectifiers an apparatus of a similar nature in which a lass or vitreous envelop is used and in whic it is necessary to prom e means for conducting electrical energy from the power circuit to the space inclosed by the envelo Platinum is well suited for use as a leading-in conductor for the current in aparatus of this nature, both because of the act that it has a coeficient of expanslon which is substantially the same as that of ordinary glass'an dalso because it is nonoxidizable and always presents a clean contact surface to the material of the envelop. On account of these advantages the seal made with a platinum conductor is not affected by changes in temperature and it 15 comparatively easy to secure a close adherence of the enyelop to the metal.

The great cost of platinum'has always been, however, a serious objection to its use for such purposes and many efiorts have been made to secure a suitable substitute. By makin a compound wire of two or more metals or y choosing suitable alloys, conductorszhave been prepared which have a temperature coeficient very nearly if not exactly the same as that of the material used for such envelope. Attempts have also been made to produce seals with conductors having a somewhat difierent coefiicient of expansion than the material of the envelop. For various reasons, however, dificulty has been experienced in making seals with these substitutes which will be absolutely air-tight and permanent in character. One of the causes of failure to secure 0d results in the use of such conductors is the fact that they are usually covered with a thin and porous coatin of oxid. This film of oxid prevents the ormation of a close union between the material of the envelop and the leading-in conductor and the resulting seal is not eficient. While in some instances the and will be absorbd by the glass and a tight seal can be made, the making of such a seal requires special care and skill on the part of the o erator and also takes more time than the ormation of a platinum seal.

I have found, however, that if the conductor is covered with a thin coating of a borate, made to adhere closely to the wire by the application of a temperature suflicient to bake it, the borate coating is readily absorbed by the glass and a perfect seal'can be easily and quickly made whetherthere is any oxid coating on the conductor or not. This film of borate also rotects the conductor from further oxidat1on when the heat necessa for the sealing in operation is applied. ne way by which this change can be made to take place is to coat the conductor with a film of borate and then subject it to a temperature preferably considerably higher than that required to fuse the borate. As a result I secure a hard closely adherent film like coating which, if there is any oxid on the wire, is colored accordingly. If the wire i perfectly free from oxid the coating will be transparent. What the exact nature of this coating upon oxid covered wire is I am unable to state definitely but from the behavior of the coatinn in the sealing-in operation it seems very ikely that it consists of a chemical combination of the original borate with the oxid. One form of conductor which I have treated in this way with very satisfactory results is one com osed of a core of an alloy of iron and nicke surrounded by a' sheath of copper. The parts of this conductor are so chosen that it has practically the same coeficient of expansion as glass. 1 have, however, made perfect seals with conductors prepared by my process and having a substantially dfli'erent cocficient of expansion than glass, as for example, a solid copper conductor. perlments, in fact, have led me to believe that the method which I use is of great utility if applied to any conductor whose conducting properties are such that it is suitable for a leadin conductor.

1 have found t at borax Na B 'O is well adapted for use in forming this film on the conductor though her-ates of zinc, copper, and other. metals may also be successfully employed.

My invention will be best understood by reference to the accompanying drawing-in which I have illustrated one of thenumerous ways in which the coating may be formed on the conductor and in which F gu 1 is an elevation of the complete a paratus and Fig. 2 is a section through the e M of Fi 1. The conductor 1 which is to be treate is unwound from the r eel 2 and passed through a tank 3 contalnmg a concentrated solution of the borate which is to be used to form the desired coating. The solution may be kept heated by means of a hot plate 4 on WhlCh the tank rests or by any other convenient method. The wlre 1s ided in its assalgle through the solut on y means of t e leys 5, 5, under WhlCh it passes. After caving the tank the conductor is passed over the hollow guide 6, and through a furnace 7 in which the deposlt 1s bakedon to the conductor. It is then wound upon a reel 8 and is ready for use for sealing into the lamps. In order to rovlde a constant supply of the concentrate solutlon to re lenish the tank 3 a hollow funnel 9 may e located directly over the groove 10 of hollow guide 6, which funnel conta ns a supply of the borate which is to be used. Water is allowed to drip from the tank 11 through this borate and the concentrated solution thus formed passes down through the funnel into the groove 10 and from thence flows into the tank 3. In orderto keep this art of the apparatus heated so that the so ution supplied will always be at the desired temperature steam is led into the hollow wall of the funnel 9 through the p1pe 12. This steam pames from the hollow wallof the funnel through the connecting pipe 13 to the interior of the hollow g1ude from thence it passes by the connecting pipe 14 to the heating coil 15 in the tank 11 and thus provides a supply of hot water for forming the solution. The stop cock 16 controls the su ply of water in or er to provlde the desired amount of solution. To prevent the wearing of the guide a hardened steel insert 17 may be placed in the groove. over which the wire passes. The

furnace 7 may comprise a porcelain tube 18 around which is wound a heating coil 19 designed to bring the furnace to a temperature high enough to bake the coating on the wire. I have found that when a copper conductor or a copper sheathed conductor is used with borax a temperature of\800 to 900 0. gives the best results. Both ends of the furnace are open to the air and the tube is covered with a body of non-conducting material 20' inclosed in a casing 21'; When the conductor enters the furnace the 'water of the solution is first evaporated'leaving a;,thin and uniform coating-of the borateonits surface. The water. of crystallization is driven off and the coating melted and baked until it becomes hard. If there is a layer ofoxid on the conductor the coatingtakes on the same color or approximately the same. color weep-1.7

as the oxid. If there is no oxid present the coating is transparent.

This coating adheres closely to the conductor and when brought into contact with the material of the envelop at the high temperature necessary for the sealing-in operation, protects the wire from further oxidationt, is readily absorbed by the glass, and a per the action which takes lace between the leading-in conductor an the material of the envelop I am unable to state at the present time. Ihave found, however, that the time required for formin less than that required when a conductor is used without any coating or with a coating applied without the use of heat, the temper ature required is not as great and a reater percentage of the seals made are perfect,

What I desire to secure by Letters Patent of the United States, is

the seal is much ect seal formed. The precise nature of 1. The method of improving the seal form ing property of a leading-in conductor other than platinum which consists in the formation on the surface thereof of a moisture free coating of a borate.

2. The method of improving the seal forming property of a leading-in conductor other than platinum which consists in the formation on the surface thereof of a baked-on coating of a borate.

3. The method of improving the seal formmg property of a leading-in conductor of a base metal or metals which consists in the formation on the surface thereof of a bakedon coating of a borate.

4. The method of improving the seal formng property of a leading-in c'onductor havmg a copper surface which consists in the formation on the surface thereof of a bakedon coating of a borate.

5. The method of imparting to an electrical conductor other than platinum the property of platinum, of readily formin a pers1stent air-tight oint with glass which consists in the thereof of a baked-on coating of a borate.

6. The method of 'impartmg to an electrical conductor of a base metal or metals the property of platinum, of readily forming a pers stent air-tight joint with glass which consists in the formation on the surface thereof of a baked-on coating, of. a borate.

7. The method ofimparting to an electrical conductor having a copper surface the property of platinum, of readily forming a pers stent a1r-tight oint with glasswhlch consists 1n the formation on the surface thereof of a baked-on coating of a borate.

8. The method of imparting to an electrical conductor of a base metal or metals having a film of oxid on its surface, the property of platmun 1, of readily forming a pers1stent air-tight Jomt withglass which weaea'r 11. A leading-in conductor having a cu-.

preous surface covered with a baked-on coatmg of a borate.

12. A leading-in conductor composed of a base-metal or metals having an oxidized surface covered with a baked-on coating of a berate- 13. leading-in conductor of a base-metal or metals having a surface'layer composed of 0nd of the surface metal combined with a borate.

14. A leading-in eonductor having a eupreous surface covered with a layer of copper oxid combined with a borate.

15. A leading-in conductor having a moisture free coating of a borate.

16. A leading-in conductor of a base metal or metals and having a moisture free coating of a borate.

17. A leading-in conductor having a c preous surface covered with a moisture free coati of a borat e.

18. leading-in conductor composed of a base metal or metals having an oxidized 'surfiace covered with a moisture free coating of a borate.

19. A leading-in conductor of a base metal or metalshaving a surface layer composed .of om'd of the surface metal combined with a borate.

20. A leading-in conductor having a cu- I preous surface covered with a moisture free ayer of copper" oxid combined with a borate.

21. A leading-in conductor consisting of copper sheatEhaving a baked-on layer of a borate.

22. A leading-in conductor consisting of a core of an alloy of nickel and iron and a copper sheath having a moisture free coating of a borate.

In witness whereof, I have hereunto set, my hand this 24th day of December, 1913.

, WILLIAH LLOYD VAN HUBER.

Witnem:

' S. N. Wm'rman,

J. H. Emma.

. a core of an alloy of nickel and iron and a 

